Microsoft Corp. has clarified statement of its chief executive officer about 500 million licenses of Windows 8 to be sold in 2013. The firm claims that Steve Ballmer re-stated what was said during the unveiling of Windows 8 Store back in December, 2011. Apparently, 500 million is a potential number of users, who will upgrade to Windows 8 from Windows 7.

“The stat Steve Ballmer gave at the Seoul Digital Forum was a restatement of the same data already announced in December at the [Windows 8] Store event regarding the number of Windows 7 devices that could potentially upgrade to Windows 8,” said an official for Microsoft, according to media reports.

During the announcement of Windows 8 Store the software giant indeed indicated that half a billion of PCs may be upgraded to Windows 8 and therefore pose opportunities to software developers who design software for the virtual store aimed at the operating system.

"We have just passed the 500 million licenses sold mark for Windows 7, which represents half a billion PCs that could be upgraded to Windows 8 on the day it ships. That represents the single biggest platform opportunity available to developers," said Ted Dworkin, partner program manager for the Windows 8 Store.

While it was not very likely that Microsoft would have sold 500 million Windows 8 licenses by end of 2013, it is even more unlikely that over 500 million users would swap Windows 7 to Windows 8 on their existing PCs in the first year, if ever at all. In fact, given that Windows 8 looks like an operating system for a smartphones on steroids and lacks a number of visual effects and common tools, loads of users will probably try to use their Windows 7-based PC systems for as long time as possible.

Microsoft Windows 8 operating system will be available in three versions later this year. Two versions will be designed for x86 processors and one will be aimed at ARM-powered systems. All three will support touch-screen, keyboard and mouse, all general capabilities of Windows and Metro-style apps. The version for ARM will also include touch-optimized versions of Microsoft Word, Excel, PowerPoint and OneNote, but will not run Windows applications designed for x86 processors.